How to use Industrial Hydrocyclone Desander& Classifier Sizing Calculator
- Enter Feed slurry design total flowrate (m³/h) and adjust the options as needed.
- Run the tool and inspect its results, evidence and limitations.
- Copy or download the result, then verify it against the actual website, source data or business records.
Try a concrete example
For a gold and silica sand beneficiation plant closed-circuit grinding stage with a design feed slurry rate of 60.0 m³/h at 1.5 bar (150 kPa) inlet pressure, ore solid density of 2.65 t/m³, water carrier density of 1.0 t/m³ (density differential 1650 kg/m³), and 20.0% solids by weight, employing a polyurethane wear-resistant cyclone with Dc = 150 mm for desanding classification: Bradley cyclone kinetics calculate a cut size d50 of 278.0 um; underflow spigot slurry rate is 21.0 m³/h thickened to 57.1% solids; overflow rate is 39.0 m³/h with clarified 0.5% solids; recommended tangential feed nozzle diameter is 38 mm (0.25 Dc), vortex finder bore is 53 mm (0.35 Dc), and spigot apex throat is 30 mm (0.20 Dc). Underflow discharges in a clean 25° umbrella spray with an open axial air core and peak classification efficiency.
How to interpret results
Hydrocyclones (desanders/deslimers) are static separation units with no moving parts that utilize tangentially fed pressurized fluid to induce high centrifugal acceleration (hundreds to thousands of g's) for solid-liquid classification and thickening. Slurry pumped through an involute or rectangular feed nozzle forms a high-speed outer downward vortex along the cylindrical and conical body walls. Coarse or dense particles with large centrifugal inertia are forced outward and slide down the cone walls, discharging through the apex spigot as underflow. Fine particles and carrier fluid reverse axially near the cone tip, forming an inner upward helical vortex inside the central low-pressure core and discharging through the top vortex finder as overflow. The Bradley and Dahlstrom empirical models relate geometric proportions, feed pressure, and phase density differentials, forming the benchmark standard for closed-circuit grinding, slurry tunneling, and oilfield solids control.
Frequently asked questions
What is the mineral processing physical definition of the classification cut size d50 in hydrocyclones?
The classification cut size d50 (Separation Micron) is the critical equivalent geometric particle diameter (in um) that has exactly a 50% probability of reporting to the underflow and a 50% probability of reporting to the overflow in the centrifugal flow field. The vast majority of particles coarser than d50 (80% to 95%+) are separated by centrifugal force into the spigot underflow, whereas particles finer than d50 entrain into the upward inner vortex to exit through the overflow. A smaller d50 represents finer classification. For geometrically proportional cyclones, d50 scales positively with body diameter (d50 proportional to Dc^0.66) and inversely with feed pressure and solid-liquid density differential (d50 proportional to P^-0.28 * Delta_rho^-0.5).
What is the essential distinction between umbrella spray and roping discharge at the cyclone underflow, and how should roping be corrected?
First, optimal classification displays an umbrella spray discharge: underflow exits the spigot as a hollow conical flared spray with a 20° to 30° included angle. A distinct negative-pressure air suction void exists at the vortex center, confirming an unimpeded continuous axial air core, thorough centrifugal phase separation, and maximum sharpness of cut. Second, overloaded roping discharge manifests as a dense solid columnar twisted stream. This indicates the spigot throat is choked by solids, underflow capacity has reached its physical limit, and the central air core is extinguished. Coarse solids are forced upwards into the overflow, ruining downstream separation. Corrective actions require immediately enlarging the spigot nozzle diameter (installing a larger ceramic apex), diluting feed solids concentration, or adjusting feed pump pressure.
Why must ultrafine classification (e.g. d50 < 20 um) employ manifolded clusters of small-diameter cyclones operating in parallel?
Centrifugal acceleration scales as a = v^2 / r. Classifying sub-micron and ultrafine particles requires extreme centrifugal forces (1000g to 2000g+). Large cyclones (Dc = 500 to 660 mm) have large radii and weak centrifugal acceleration, yielding cut sizes of 75 to 150 um. Miniature cyclones (Dc = 50 to 100 mm) have very small radii, accelerating sedimentation to reach sharp cut sizes of 10 to 25 um. However, individual miniature cyclones have low flowrates (only 2 to 10 m³/h). To meet industrial throughputs (200 to 1000 m³/h), dozens or hundreds of small cyclones are arranged in a circular cyclone cluster manifold operating in parallel under balanced pressure.
How does feed inlet operating pressure govern hydrocyclone cut sharpness versus abrasive liner wear?
First, benefits of higher feed pressure: elevating inlet pressure from 0.5 bar to 1.5-2.0 bar increases tangential entrance velocity and centrifugal acceleration, refining cut size d50 by 15% to 25% while boosting underflow solids concentration. Second, severe abrasive wear penalties: slurry abrasive wear against cylinder walls scales with velocity to the 3rd to 4th power (Erosion proportional to v^3-v^4). If pressure exceeds 2.5 bar, ceramic or rubber liner life drops from 6-12 months down to weeks, while pump power spikes. Closed-circuit grinding operations recommend feed pressure maintained strictly within the 1.0 to 1.8 bar economic window.